A delta motor system typically includes a delta motor, a three phase power source, a fault contactor and a motor controller. The motor controller generally includes a set of three control switches that are connected between the line voltage terminals of the three phase power source and the windings of the delta motor. The motor controller regulates the voltage from the three phase power source to the delta motor by selectively opening and closing the three control switches. The proper operation of the delta motor is dependent on the proper regulation of the control switches.
During start up, the controller, also referred to as a soft starter, controls the switches to provide reduced voltage starting until the motor reaches full speed. The motor controller's internal timing mechanisms are specifically designed to regulate the application of specific line voltages from the three phase power source to specific delta motor windings based on a predesignated wiring configuration. Conventional electrical leads are typically used to connect the delta motor windings to the control switches and to the fault contacts. Since the electrical leads providing connection to the delta motor terminals are not always clearly marked, mistakes in wiring the delta motor system are common. If the winding leads are swapped, resulting in the windings being driven relative to different power source phases than required, then the soft starter may not be able to supply a reduced voltage start or may not be able to supply full voltage to the motor after starting. This can also damage the motor and the soft starter.
The present invention is directed to solving one or more of the problems discussed above, in a novel and simple manner.